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Puppet overview


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Quick Puppet introduction

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Puppet overview

  1. 1. Puppet Master Class Puppet overview
  2. 2. About Me: Miguel Rodrigues DevOps using puppet 3 years lousy creator of slidesets
  3. 3. What is puppet CM tool - Bring running systems to consistent state; Despite the starting point systems will end in the same point, in a repeatable and predictable way; Other CM tools : Chef, Ansible, Salt, Capistrano…..
  4. 4. What is the need for a CM ? Admin one, two … servers is nice … do it on 1000 is awful boring repeatable ….. To Err is Human; To Really Foul Things Up Requires a Computer…. image the mess in 100's or 1000's of computers
  5. 5. @WikiLovers Started by Luke Kanies in 2005 founded Puppet Labs GPL Unix* and Windows Ruby Have one language (DSL) more details: Wiki for it ;-)
  6. 6. Declare where you want to be ( not how to get there ) - presenting Manifest’s file: some_manifest.pp node ‘some_name_or_ip’ { …. do_stuff_to_get_servers_where_You_want …. } puppet apply some_manifest.pp
  7. 7. Hold on … Are there any requisites ? Need running system ( bootstrapping is another issue, more on that later ) puppet installed ( How2 and dependencies are OS specific )
  8. 8. Do Stuff puppet apply classes to nodes classes are set of resources and resources are ….
  9. 9. Some Resources Examples package file service cron exec notify user ….. Full list of resources at
  10. 10. Facts: "that is life" We take decisions based on facts , so puppet can do it Facts are variables to puppet environment facts others ( eg: this server is “yellow”) facts can ( should be ) used in classes
  11. 11. Confused ??
  12. 12. Ntp and Time, one classic example Challenge What time is it ? Systems need to be accurate update logs with timestamps do action based on time Network Time Protocol (NTP) is a networking protocol for clock synchronization
  13. 13. Basic Ntp on a server (variables, resources and templates) file: some_manifest.pp node ‘some_name_or_ip’ { $package_name= “ntp” $host_config = “xpto” $ntp1 = “ip_or_address_1” $ntp2 = “ip_or_address_2” package { $package_name: ensure => installed, } file { 'ntp_config_file': ensure => file, path => '/etc/ntp.conf', require => Package[$package_name], content => template('ntp.conf.erb'), mode => '0644', owner => 'root', group => 'root', } (variables in orange and resources in red) service { 'ntpd': ensure => running, name => 'ntpd', enable => true, subscribe => File['ntp_config_file'], } } puppet apply some_manifest.pp
  14. 14. Templates … Files Files are used to configure services The content can be static ;-( or should be based on environment Templates can add Dynamic content Based on variables have ruby logic in it ( if/else, cycles, …. )
  15. 15. Ntp template (ntp.conf.erb)- template example restrict default ignore <% if @host_config == "some_value" -%> server <%= @ntp1 %> <% else -%> server <%= @ntp2 %> <% end -%> server fudge stratum 10 driftfile /var/lib/ntp/drift broadcastdelay 0.008 keys /etc/ntp/keys restrict
  16. 16. Not a clever way to code , Modules are here Modules are self- contained bundles of code and data. file: some_manifest.pp node ‘some_name_or_ip’ {class { 'my_ntp_module':}} file: ./modules/my_ntp_module/manifests/init.pp class my_ntp_module { …. same do_stuff …. file { 'ntp.conf': …. content => template('my_ntp_module/ntp.conf.erb'), .. } } file:./modules/my_ntp_module/templates/ntp.conf.erb puppet apply --modulepath ./modules/some_manifest.pp
  17. 17. Clever Modules … Arguments file: ./modules/my_ntp_module/manifests/init.pp class my_ntp_module ($package_name, $host_config, $ntp1, $ntp2) { …. same do_stuff …. } } file: some_manifest.pp node ‘some_name_or_ip’ {class { 'my_ntp_module': package_name => “ntp” host_config =>“xpto” ntp1 => “ip_or_address_1” ntp2 =>“ip_or_address_2” }} puppet apply --modulepath ./modules some_manifest.pp
  18. 18. Code and data “all together” :-(... welcome to backends (Hiera) Purpose separate data ( values) from logic (code) support multiple data types (values, list, hash ….) Hiera is a key/value lookup tool for configuration data Hiera can use several different data backends, including two built-in backends ( yaml and JSON ) and other optional ones.
  19. 19. Data Encryption Why ? Secrets should be kept … secret “someone” should know about Secrets Backends may be encrypted when and where needed for a list of “trusted persons"
  20. 20. Modules with backend file: ./modules/my_ntp_module/manifests/init.pp class my_ntp_module ($package_name, $host_config, $ntp1, $ntp2) { …. same do_stuff …. } } file: some_manifest.pp node default { hiera_include('classes')} node ‘same_name_or_ip’ {class { 'my_ntp_module':}} file: hieradata/backend.yaml my_ntp_module::package_name: “ntp” my_ntp_module::host_config: “xpto” my_ntp_module::ntp1: “ip_or_address_1” my_ntp_module::ntp2: “ip_or_address_2” puppet apply --modulepath ./modules --hiera_config hiera.yaml -- some_manifest.pp
  21. 21. Where Manifests (and related stuff) are? Manifests (and resources specified in it) must exist on the system at the time they are applied They go there “by magic”: “Someone” send them to the system ( push approach) fetched from some place ( eg: VCS like git, svn, … ) (pull approach ) “just are there”
  22. 22. Bootstrapping Servers How ? :-( “manually” CF/ AMI …. in AWS PXE boot ( in “DC”) Heat ( in Openstack) others ...
  23. 23. Bootstrapping Servers - Process (1) 1.Install OS 2.“Hard” install a.Set keys for VCS authorization b.Set facts for the host (product/env/role/location/… ) c.Set hostname, and "basic stuff"
  24. 24. Bootstrapping Servers - Process (2) 3.“Soft” install a.Fetch manifests code and backend data from VCS based on facts b.Apply puppet